The trend of mobile communications is to generalize the transmission of short size packets and designers of mobile communication systems are constantly concerned with the problem of maintaining high transfer rate despite the locally fixed and potentially severely faded profile of the transmission channel
Techniques are already known for maintaining a high transfer rate and for preventing the loss of packets in short-time transmissions, by increasing diversity.
Designers may take advantage of the known Cyclic Delay Diversity (CDD) technique based on the addition of new antennas for improving the communication through the channel being considered.
Alternatively, there is given the possibility to use hoping frequency techniques which is based on OSI layer-3 control procedures and signaling techniques allowing both mobile and the base station to switch the communication to a different set of subcarriers.
Because such hoping techniques involves the use of signaling process between the mobile and the base station, such techniques can clearly only be considered for long attenuations of the channel extending over several milliseconds.
It should be noticed that the problem of short attenuation of the channel is particularly critical in an urban environment, when the mobile is closer to the base station.
Those techniques are not usable for shorter attenuation of the channels, which might cause the loss of the whole packet.
There is therefore a need for an alternative technique, close to the physical layer with respect to the OSI architecture, which takes into account the short attenuation of the channel and thus the instantaneous data rate of a digital communication.